I think is a mistake to try to validate the barbaric actions that people like this criminal commit. A phenomenon that happens with revolutionary movements is that a lot of common criminals will join, not for ideological reasons but for personal reasons or just as a way of getting even with the system.
I know of some people with very questionable credentials, some of them in prison for common crimes who became leaders of revolutionary movements and they are today "heroes of the revolution". In reality they were thief's, murderess, rapist and many other delinquents.
So like I say is not wise to attach any ideological justification to atrocities like this one.